Radiation and Radiological
John Gough, MS, CHP, CMLSO
Radiation Safety Officer
Swedish Medical Center
• Radiation Basics
• Common Radiation Sources
• Radiation Dose Limits and Emergency
• Radiological Events as they relate to possible
future events
• Q&A
• A Radiological Event involves the accidental or
purposeful release of radiation or radioactive
materials into the public or environment
• This can create fear, injury and death and lead
to severe disruption.
– Fear is due to the public’s general fear of radiation.
– Injury and death may be the result of the explosive
and could result from sufficient radiation exposure.
– Disruption results from of panic and the cleanup of the
radioactive material and any consequent avoidance of
the radioactive location after clean up.
Roentgen’s Discovers X-rays
November 8, 1895
Becquerel and Curie’s
Discover Radioactivity
(Uranium ore)
August 1, 1903
Radiation as seen by public
Radiation Reality
Been studied for over 100 years
Is naturally occurring
Characterized very well
Risk are well known for high levels
Have a lot of human data
Weak carcinogen
Weak mutagen
Saves thousands of lives
Common Uses of Radiation /
• Medical – (Nuclear Medicine,
Radiation Therapy, X-ray)
• Industrial Radiography –
(Structural Testing)
• Sterilization – (Blood Sterilization)
• Consumer products – (Smoke
Detectors, Tritium Luminescent
Radiation Physics
• The most basic definition of radiation is the transfer of
energy from on location to another. For example a car
hitting a tree.
In very simple terms it is the transfer of
energy from one location to another.
• Radiation is defined as energy in transit as either
electromagnetic wave or energetic particles.
Ionizing vs. Non-Ionizing
• Non-Ionizing Radiation
– Transfers energy by heat conduction
– No chemical effects
• Ionizing Radiation
– Has the ability to induce chemical changes
– Transfers very little energy relative to biological damage
Types and Properties of Radiation
Roentgen (R)
Rad or Gray
Rem or Sieverts
Radioactivity (Bq) – Attributed to
material and describes the number of
emissions occurring in a given time
Curie (Ci)
Radiation Production
• Radioactivity
– Continuously emitting
radiation (no off switch)
– e.g. Tc-99m, Uranium
• Machine Sources
– Only emits when on
– e.g. X-ray Machine
• A measure of the amount of time for ½ of the activity
to disappear
• Given enough time all radioactive materials will decay
to background levels.
Some radioactive isotopes and their
110 minutes
6 hours
8 days
74 days
30 years
1600 years
4.5 billion years
Radiation Sources
Sources of Background Radiation
Radiation Doses – Medical Procedures
Cardiac Stress Test – 730 mrem
Chest x-ray PA – 2 mrem
CT – Chest / Ab / Pelvis – 1800 mrem
Lumbar Spine Series –
180 mrem
I-131 Thyroid CA Therapy –
22,000 mrem
Bitewing Dental X-ray – 0.4 mrem
http://www.doseinfo-radar.com/ from the RAdiation Dose Assessment Resource
Typical Radiation Doses
Astronaut in space for 1
month, 15,000 mrem
Average US Smoker
5300 mrem to the lungs
630 mrem whole body dose
TSA X-ray Screening Device
0.1 mrem or less per scan
Round Trip – NY to LA
10 mrem
Living in Denver, CO vs. Seattle WA for 1
year – 25 mrem (additional cosmic
radiation exposure due to altitute)
Biological Effects
Acute effects generally do not occur for radiation dose below 25 rem (25,000
mrem). They also do not appear when doses are delivered over a prolonged
period of time.
Industrial Radiography accident
due to handling of a radiography
source - 2001
Fluoroscopy “burn” early 1990
Hair loss as a result of a CT
Brain Perfusion Scan at Cedar
Sinai, 2008-2009.
Acute Radiation Effects
(Total Body Exposures)
Dose (rad)
Whole Body
Time to Onset
Blood Count Changes
Days to 1 Month
Physiological Effects
Hours to Days
LD 50/60 (no medical care)
2 Months
LD 50/60 (medical care)
2+ Months
850 – 900
100% fatal
GI Syndrome
CNS Effects
Chronic / Delayed Effects
• The Risk of cancer from exposure to radiation is well
documented for exposure to radiation doses above 10 rad
(single exposure, not exposure over time).
• The risk from single exposure below 10 rad or chronic low level
exposures (e.g. occupational doses) are postulated based on
statistical analysis. There are no epidemiological studies that
confirm or deny the effects of single doses below 10 rad or from
chronic low level exposure where the only radiation is involved.
• Risk data is primarily derived from studies of the survivors of
Hiroshima and Nagasaki.
• Delayed / Chronic effect typically show after a latency period
that can be from 5 years to more than 50 years.
Cancer Risk
• Cancer risk is derived from
Japanese bomb survivor
• Background Cancer risk in
the US is approximately
42%, fatal cancer risk, 23%
• 0.0005 risk per rem = 1 in
2,000 chance of fatal cancer
per rem of exposure (general
• 1 in 1,000,000 risk of fatal
cancer from a Chest X-ray
Biological Effects of Ionizing
Radiation (BEIR) VII Report (2006)
Activities with a 1 in
1,000,000 risk of fatality
Driving a car 80 miles.
Driving a motorcycle 2.6 miles
Riding a bicycle 26 miles
Eating 43 TBSP of peanut butter. About 1 jar.
Risks from Everyday Activities
Smoking 10 cigarettes/day
Playing Soccer
Hit by Lightning
1 in 200
1 in 6,000
1 in 100,000
1 in 10,000,000
Fishing and Logging
Coal Mining
Police Officer
Construction Industry
1 in 1,000
1 in 3,600
1 in 4,000
1 in 6,000
1 in 6,000
1 in 10,000
Dose Limits and
Exposure Recommendations
Radiation Dose Limits
Part of Body
Annual Limit
Whole Body (TEDE)
Organ or Extremity
Lens of the Eye
Dose to Fetus (Radiation Worker)
General Public (individual)
*WAC 246-221-010 and 055, 10 CFR Part 20
Federal Protective Action Guide
Dose Limit
(Whole Body)
Emergency Action Dose Guidelines
5 rem
All Activities allowed (maximum whole body
dose limit for occupational workers)
10 rem
Protection of major property only
25 rem
Lifesaving or protection of large populations
>25 rem
Lifesaving or protection of large populations.
Only by volunteers who understand the risks.
EPA Protective Action Guides - 1992
Federal Protective Action Guide - Revision
Dose Limit
(Whole Body)
Emergency Action Dose Guidelines
50 rem
Lifesaving or protection of large populations –
By Volunteers
>50 rem
Lifesaving or protection of large populations.
Only by volunteers who understand the risks.
ICRP (1991), NCRP Report No. 116 and NCRP Report No. 138, DHS (2007)
Decontamination Limits
• Standard Limits USNRC and NCRP
(Unrestricted Access to Property) (Has
also applied to personnel contamination)
– 2000 dpm / 100 cm2 (beta/gamma) – 1 nCi
– 200 dpm / 100 cm2 (more hazardous
beta/gamma) – 0.1 nCi
– 20 dpm / 100 cm2 (source material) – 0.01
– 2 mR/hr (for fixed sources, no removable
Activity Magnitudes
Use or Where typically found
1 pCi (10-12 Ci)
Quantities found naturally in the environment
1 nCi
Typical Decontamination level
1 uCi
Typical laboratory research quantity
1 mCi
Diagnostic administration of radioactivity for
nuclear medicine studies
1 Ci
1000 Ci
Therapeutic administration of radiation (cancer
Sterilization (Blood irradiators)
Radiological Events
International Atomic Energy Agency (IAEA)
Supplementary Radiation Symbol approved in 2007.
Radiological Accident Statistics (1945-2007)
• About 50 (documented) accidents in the US involving
radioactive material/radiation sources.
– 400+ worldwide
• 33 (documented) fatalities in the US (over ½ from medical
– 100+ worldwide
• 230+ (documented) radiation injuries in the US.
– 3000+ worldwide
• 28 documented criminal acts involving the use of radioactive
material/radiation to cause injury/death (6 in the US,
remainder in USSR/Russia, Taiwan and London)
Types of Radiological Events
• Atomic/Nuclear Weapon
• Accidental Release of Radioactive Material
– Reactor Accident
– Transportation Accident
– Loss Source
• Radiological Dispersal/Exposure Device
– Explosive
– Non-Explosive (~12 documented criminal cases
NY Times, April 23, 2010
Scrap Metal Radiation Raises Concerns in India
• April 2010 – Mayapuri, India
• Co-60 Gamma Cell Irradiator
(unused since 1985 from New Delhi
University) sold as scrap metal at
auction in Feb 2010.
• Dealer cut the Co-60 cell into 11
• 8 injured, 1 death
Nuclear Device
Hiroshima, Japan
• 15 kilo-ton U-235 (80%
enriched) bomb
• Population 385,000
• Immediate damage radius
~ 1 mile
• 80,000 (est.) fatalities
(most from blast injuries
(about 80%) – with 70% of
the remaining 20% dying
within the first two months.
Photograph from HMS Vengeance
November 1945
Hypothetical Improvised
Nuclear Device
• Based on “Planning Guidance for Response to a
Nuclear Detonation” Homeland Security Council
- 2009
– Hypothetical planning is based on a 10 kT device
(Same destructive magnitude as devices used in
Hiroshima and Nagasaki)
– Blast Damage Radius of 3 miles and fallout radius of
20 miles
– Casualty statistics are not specifically determined in
the report but values can be determined from a
comparison of the effects to populations at Hiroshima
and Nagasaki vs. population of the affected area.
Projected Impact of a 10 Kiloton
Improvised Nuclear Device
Depiction of fatalities in
Seattle from a 10 KT IND.
Ground Zero is the
Coleman Dock. Based on
Presidential Directive #8.
~50,000 dead
3-5 Hospitals affected
(Swedish FH, CH and
Harborview, Group
Health Central and
Virginia Mason)
Infrastructure damage
out to 1 mile
450,000 evacuated
Contamination ~3,000
sq miles
$100+ billion in costs
Accidental Release of
Radioactive Materials
Tokai-Mura – Criticality Accident
Tokai-Mura – Criticality Accident
• September 30, 1999, three individuals were exposed to
high radiation doses (1700, 800 and 300 rem)
respectively (2 subsequently died).
• Authorities instructed over 300,000 people to remain
indoors (shelter-in-place) for 1 day (within 10 km of the
• 150 people were evacuated.
• 347+ individuals identified as being exposed to levels of
radiation above allowed public dose limits (100 mrem)
• 20 individuals received radiation doses between (5 and
25 rem) (workers who stopped the chain reaction)
One of the three irradiated workers
Over the next 10 days 10,000+
individuals sought radiation
Tokai villager is scanned for
A total of 76,000 individuals were monitored
for surface contamination.
5,700 individuals visited offices for health
Tokai - Demographics
• Tokai village – population ~35,000
• Ibaraki Perfecture (county) - ~ 3 million
• Near the accident site, 5 major
hospitals, 3 secondary hospitals and 1
tertiary hospital.
• 788 medical personnel (55 MD, 220
public health nurses, 39 RN, 144 RT,
330 others) were involved in the
response at 5 centers.
Swedish’s former RSO and Rad Safety Specialist reported that several
individuals were provided radiation safety surveys at their request due to
concerns of being in Japan at the time of the accident (flight crews and
Fukishima Daiichi
March 11, 2011 – April 14, 2011
• March 11, 2011 – Magnitude 9.0 Earthquake off the
coast of the Tohoku Peninsula and subsequent 12 meter
high tsunami that hits the northern coast of Honshu
• Fukishima Daiichi is a group of 6 boiling water nuclear
reactors with a total capacity of over 4,500 MW(e)
(roughly the capacity necessary for 350,000 homes in
the US)
• Only 3 of the 6 plants were operating at the time of the
tsunami with a 4th defueled.
• Plants and generators were designed to
withstand a 5.7 meter high tsunami (18.7 feet).
• The following day battery power on for the
reactor cooling system failed resulting the
various events that leads to the uncontrolled
release of radioactivity into the environment.
• Beginning March 15, 2013, measured
increases in public exposure in Japan, but not
at levels that would lead to any significant
change in epidemiology.
Public Fears Radiation
• Residents flee Tokyo and make a run on
US Officials Don’t Understand
Radiation Hazards
• March 15, 2011 - U.S. Surgeon General
Regina Benjamin is in the Bay Area
touring a peninsula hospital. NBC Bay
Area reporter Damian Trujillo asked her
about the run on (KI) tablets and Dr.
Benjamin said although she wasn’t aware
of people stocking up, she did not think
that would be an overreaction. She said it
was right to be prepared.
1.3 pCi / m^3 of I-131 detected
Would lead to a radiation dose of 1.5 mrem if an individual
were to breathe this concentration for 365 days 24 hr/day.
• Evacuation radius of 20 km, displacing 70,000 residents
• About 116,000 individuals were screened for
radioactivity with detectable activity found on 102
individuals (limited to clothing in all cases, no intake
• Food and drinking water restrictions were implement for
the local area on March 19 and removed on April 2.
• Ongoing stigma with regards to foods / products
produced in the area.
• 17 injuries (15 from explosion/thermal injuries, 2
radiation exposures)
Radiological Dispersal
Large Scale Release Example
Radiological Dispersal Device
• Conventional explosive device surrounded by radioactive
• Passive distribution of radiation from a stationary source
or other manual or automated dispersal.
• Radioactivity is generally not great enough to be of a
significant hazard to personnel.
• Used primarily as a device to inspire panic and fear, or in
the case of passive dispersal to specifically target an
individual or group.
• The consensus isotopes that would be used are those
commonly used for industrial radiography, medical
therapy or sterilization
Goiânia, Brazil
• 1987: teletherapy
head stolen
50.9 TBq (1375
Ci) cesium-137
machine left in
abandoned clinic
Unit dismantled,
Cs-137 source
capsule ruptured
causing major
Dose rate at 1 meter
from source: 456 rad/hr
Goiânia, Brazil
• Source stolen on Sept 10.
• Initial physiological symptoms (vomiting) on Sept 13.
• Initial medical assistance on Sept. 15, diagnosed as an
allergic reaction to bad food.
• Initial admission to hospital on Sept 23, initial diagnosis
tropical disease
• Hospital M.D. given portion of radiation source on Sept
• Physicist determined source to be radioactive on Sept
Goiânia, Brazil
• 85 houses significantly
• 200 people evacuated
• 7 houses demolished
• 12,000+ 55 gallon drums
(equivalent volume) of waste
Goiânia, Brazil
Exposure of large number of public:
• 4 deaths (initially), 5th died in
• Prussian Blue was administered
to 46 individuals
• 49 received doses from 10 to
620 rad
• 249 had some level of
radioactive material
• 112,000 were monitored for
radioactive material
Goiânia - Demographics
• Goiania – population
~1.27 million
• 12th largest city in Brazil
• Incident involved 3
hospitals in Goiania and 1
in Rio de Janeiro
• Radiation monitoring
performed at soccer
Rio de Janeiro
Radiological Dispersal
Small Scale Release Example
London, UK
• Nov. 1, 2006 – Former Russian Agent is intentionally
poisoned with 5 uCi or about 1 microgram of Po-210.
• Fell ill within 4 hours and admitted to hospital.
• MD suspected poisoning and radioactivity was
suggested as a possible cause on Nov. 21.
• Individual died on Nov. 23.
• On Nov. 24 death officially linked to major dose of
radioactivity ingestion.
London, UK
• 30 locations identified as being potentially contaminated
• By Dec. 5, 2006, 3,233 individuals called the British
Health Services regarding possible radiation exposure
(244 were identified in the group for follow-up)
• 238 hospital workers were investigated for possible
exposure (71 received further testing)
• All initial tests were negative, though an additional 7
individuals were found to have some level of Po-210
contamination on Dec. 7, 2006 (hotel staff).
London, UK
• In 2007, UK authorities reported that a total of 735
people were tested for Po-210 exposure.
• 596 not contaminated.
• 120 showed probable contact with Po-210 but at levels
indicating no health risks.
• 17 showed levels “not significant enough to cause any
illness in the short term and any increased risk in the
long term is likely to be very small”.
Notes Regarding
Hospital Response
Hospital Radiological
• No healthcare worker (world wide) has
ever received a radiation dose in excess of
established radiation dose limits while
caring for a contaminated individual.
• In General life saving medical care should
always take precedence over
contamination control.
Hospital Radiological
• Is a nuclear medicine department present.
• Is a physicist present (particularly a health
• Are there portable radiation instrumentation
available (survey meters).
• Does the hospital have an established protocol
for emergency response to radiological events.
Calling for Help
• REAC/TS – Radiation Emergency
Assistance Center / Training Site
• Located in Oak Ridge, TN
• http://orise.orau.gov/reacts/
• 24/7 Availability
• 865-576-1005 – ask for REAC/TS
• 1-800-NUCLEAR (State of Washington)
Planning Guidance for a Response to a Nuclear Detonation, Homeland Security
Council, Jan. 2009
Planning Guidance for Protection and Recovery Following Radiological Dispersal
Device and Improvised Nuclear Device Incidents, FEMA, DHS, Aug. 2008
Management of Terrorist Events Involving Radioactive Material, NCRP Report No.
138, Oct. 2001
NRC Review of the Tokai-Mura Criticality Accident, US Nuclear Regulatory
Commission, April 2000
The Radiological Accident at Goiania, International Atomic Energy Agency, 1988
Health Effects from Low Level Ionizing Radiation, Biological Effects of Ionization
Radiation (BEIR) VII Committee, 2006
Review of Criticality Accidents, Los Alamos National Laboratory, 2000
Manual of Protective Action Guides and Protective Actions for Nuclear Incidents, US
Environmental Protection Agency, 1992.
Guidance for Radiation Accident Management, Radiation Emergency Assistance
Center / Training Site, REAC/TS, Web Document.
Incident of Radioactive Materials Discovered in Scrap Yard Dealer Shops in New
Dehli, Government of India, Atomic Energy Regulatory Board

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